Purification By Stone

Unfortunately, my analysis confirms that the water is indeed the cause of our health problems. But then again, I suppose that we should be thankful that it isn't something even more awful. The water probably just gets a little spoiled on the way here due to the heat.

Fortunately I know how to purify the water - manganese! I even know where to get it, but it's a job for a real warrior... one like you!

There are some elementals that live to the south of here. I've heard soldiers complaining about how difficult they are to kill because they're made of stone. Rock chips they brought back confirmed that they're made of manganese, so please bring me back a few chunks.